Electronics Forum | Mon Aug 12 12:16:25 EDT 2019 | SMTA-Martial
Hi, We are using a 15mils to 5 mils step stencil with a metal blade. The 15mils area the surface is smooth and polish and in the 5mils area the surface is rough and porous because of the laser process. In the 5 mils area where there is no aperture t
Electronics Forum | Wed Feb 09 06:35:18 EST 2000 | Mark Williams
Hi We use 2 criteria... maximum void size is 10% of the solderable surface and a maximum area of voids of 10% of the maximum cross-sectional area of the ball. Any views Mark
Electronics Forum | Thu Feb 07 13:53:38 EST 2013 | hegemon
I would consider wave solder as a cycle, in that for the most part the entire board is subject to the wave. Selective Solder is a gray area in that regard, since you will be hitting one or more locations, that in total do not comprise a large percen
Electronics Forum | Wed May 02 13:02:14 EDT 2018 | emeto
Based on the pickup surface area: 1. Use the biggest nozzle possible, 2.Keep in mind that some nozzles have bigger inside diameter hole(more vacuum) 3. Keep in mind that some pickup surfaces are rigid(not really flat surface) - use rubber tip nozzles
Electronics Forum | Tue Dec 28 15:35:21 EST 1999 | Mike Naddra
Edmund, An 0603 component should not fall from the board durring an inverted reflow pass, provided that: Your land geometries are correct for the package type (Start with SM 782 guidlines)- as surface tension of the liquidous solder is what holds
Electronics Forum | Tue Sep 12 09:50:31 EDT 2006 | C.K.
There is a formula for that out there somewhere. It has to do with the part mass and the area of solderable surface. If the part mass is too great in relation to solderable surface area, the part falls off in a d/s reflow cycle. Anyone remember th
Electronics Forum | Fri Feb 15 14:38:59 EST 2013 | bmario
Hi, We are having a problem with the interpretation of the surface evaluation criteria of J-STD-003 section 4.2.2.4.2. "A minimum of 95% of each of the surfaces (i.e. each pad) being tested shall exhibit good wetting. The balance of the surface may
Electronics Forum | Fri Dec 11 16:06:18 EST 1998 | Michael Allen
G, You'll find at least one old thread in this Forum on dual-reflow if you do a search. I found one dated April 7, '98 (searched on "reflow"); this particular thread includes a discussion about the maximum weight-to-surface_area for successful dual
Electronics Forum | Tue Jun 17 08:52:39 EDT 2003 | russ
Aspect ratio = width of aperture divided by height. E.G. 6 mil stencil at 9 mil wide = aspect ratio of 1.5. Value should be 1.5 min. Area ratio - use when length and width of pad are roughly same dimension like for BGAs and 0805 and smaller R-nets
Electronics Forum | Thu Mar 04 12:49:49 EST 1999 | SMTASSY
| Are square pads more difficult to wavesolder than round pads? | I am referring to a through hole board. | Usualy square pads are for indication of pin 1 on a DIP for example. There might be a difference in the capilary affect due to a different su
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